I know.. I can't find any info on him either.  lol  Initially I thought his colorings on his body resembled an Endler a bit.  So was wondering if maybe some Endler gene mucked up with the Guppy gene.  Don't know what dad looked like as mum was pregnant when I bought her at the LFS.  She was pretty though... dorsal and tail fins were blueish/purple blotched with black.  Her tail was rather large too.  More oblong shape.  I don't know... beginning to think I just have an odd lot.  His sibling from a drop a month later than him also has a funky tail.  But his looks like it might be an upside down delta/triangle type.